Disk sharpener



Jan. 2, 1940. 'A M, RANDALL 2,185,519

DISK SHARPENER Filed March 28, 1938 Patented Jan. 2, 1940 UNITED STATE AENT OFFICE DISK SHARPENER.

Arthur M. Randall, Prairie City, Iowa Application March 28, 1938, Serial No. 198,466

Claims. (Cl. 51104) The object of my invention is to provide a disk the screw-threaded rods l4. Upon the shaft N5 of sharpener of simple, durable and inexpensive the motor is a connecting wheel II of ordinary construction in which the cutting wheel and its construction. The motor unit is substantially driving motor are assembled in a single unit balanced upon the supporting bar l2, and it is 5 which is fixed to a sliding motor unit support provided with ahandle i8 which at its rear end is 5 which is also mounted for tilting movement and secured to the motor by means of a metal strap l9 upon which the motor unit is substantially balpassed around a portion of the motor and fixed to anced and whereby an operator may convenientthe handle. Near the central portion of the lever ly and easily move the motor unit with one hand there are two bolts 20 and a cross member 2! is 10 to control the vertical movement of the cutting fixedtothe handle and to the motor unit. By 10 wheel, and further to provide means including a this means it is obvious that an operator grasplever to be grasped by the operators other hand ing the forward end of the handle l8 may convenfor conveniently and easily adjusting the motor iently and easily tilt the motor on the supporting unit horizontally and holding the cutting wheel rod l2 up and down relative to the disks to be against the disk to be sharpened by a yielding sharpened. l5 pressure controlled by the operators hand so that For the purpose of horizontally adjusting the the operator may easily and conveniently vary motor unit I have provideda lever 22 having a such pressure to meet changing conditions and forked rearv end provided with pins 23 to enter whereby disks that are bent or distorted maybe the groove l5 and thereby pivotally and rotatasharpened without damage to the disks. bly connect the lever with the motor unit support. 2

In the accompanying drawing Figure 1 shows a I have also provided a lever fulcrum device, indiside elevation of a disk sharpener embodying my cated generally by the numeral 24 and having a invention; rounded opening at one end through which the Figure 2 shows the front elevation of same with supporting rod I2 is loosely and slidingly mount- 25 a portion of the central part of the device broken ed. This fulcrum support extends laterally, as 25 away and the support for one end of the disk shown in Figure 2, and is connected by a fulcrum shaft being shown'in section, the outer ends of pin 25 with the lever 22. The operation of this both of the levers being broken away. part of the device is as follows. When the lever Figure 3 shows a detail vertical sectional view '22 is in the position shown in Fi re then the taken on the line 3--3 of Figure 2; operator may, by grasping it, move it, for in- 30 Figure 4 shows a vertical longitudinal view of stance, toward the left, whereupon the forward the motor unit support; portion of the fulcrum device will be moved to- Figure 5 shows a sectional view taken on the ward the left and the fulcrum device will then be line 5-5 of Figure 1; tilted relative to the supporting rod l2 and be .35 Figure 6 shows a sectional view taken on the frictionally held thereby in position so that a line 6-6 of Figure 2; and further movement of the lever 22 will result in Figure '7 shows a detail view of the edge of the moving the en ire m r s pp rt oward the disk with the cutting wheel adjacent thereto to right, as shown in Figure 2.

illustrate the hollow grinding effect of the cutting I have shown a set-screw 26 for firmly grip- 40 Wheel. ping the fulcrum member to the rod [2. This, 40

Referring to the accompanying drawing I have however, is not necessarily used in ordinary opused the reference numeral ID to indicate frame erations as I find in practice that an operator uprights. Between the lower ends of the frame soon learns, by manipulation of the lever 22 only,

uprights are twospaced apart horizontal beams to move the motor its cutting disk horizon- .45 l I fixed to the uprights. Near the upper end of tally to any desired position and to yieldingly hold the uprightsis a horizontally arranged supportthe cutting wheel against the disk being sharping bar l2 rounded in cross section. ened, so that the operator may at all times deter- Loosely mounted uponthe supporting bar I2 is mine by the amount of pressure he applies to the a motor unit support comprising a substantially lever 22 just how much pressure will be applied 60 cylindrical body portion l3 and two upright by the cutting wheel to the disk being sharpened.

screw-threaded rods l4, and with .a circular In some instances I have found that the disks groove l5 near one end. This support is loosely are somewhat distorted in shape and not in acmounted upon the supporting bar [2. curate right-angled positions relative to the disk Mounted upon the motor unit support is a moshaft. In such cases, if the cutting wheel were tor l6 which is held to the supporting member by fixed in its position, then it would obviously dam 55 age such disks. With my device, however, the operator may apply yielding pressure, holding the cutting wheel against the disk, and continue to apply the same pressure while moving the lever 22 toward the right or left to accommodate the cutting wheel to uneven surfaces of the disk, and I have found in practice that this feature of the invention is very advantageous.

I have indicated the disk shaft by the reference numeral 21 and the disks 28. A portion of the disk harrow frame 29 is shown attached to the disk shaft, and this may conveniently rest upon the beams l I.

Rotatably mounted upon one of the uprights II] is a shaft SE to which a belt wheel 3! is fixed. This shaft has a socket at one end to receive a squared nut 32 on the end of the disk shaft, and is provided with a set screw 33 for holding the nut in position. At the other end the disk shaft is supported by a lever 3 This lever has a screw-threaded rod 35 at its upper end to engage and rotatably support the adjacent end of the disk shaft. This lever 34 projects down between the beams H and is provided above the beams with a fulcrum member 35 extended horizontally and resting upon the beams H. The end of the lever which projects down between the beams has a laterally extended portion at 31, and fixed to this portion 37 is a friction plate 38 designed to engage the lower surface of the beams H. With this construction the said lever may freely be moved longitudinally of the beams to accommodate disk shafts of different lengths. When the disks are placed in position the lever is moved to position adjacent one end of the disk shaft, and then as the screw 35 is tightened, the lever 34 will be tilted toward the right, as shown in Figure 2, with the fulcrum device resting upon the top of the beams H, and this will move the friction plate 38 upwardly into firm contact with the under surfaces of the beams H, and in this way the lever will be clamped to the beams in the desired position.

In practical use it will be seen that with my improvement an entire unit of the disk cultivator, including its frame, may readily and easily be placed in position and clamped and slowly rotated by power applied through the pulley 3!. Then the motor may be started and the operator may, with one hand applied to the lever l8, conveniently and easily control the up and down tilting movements of the cutter wheel, and with the other hand grasping the lever 22 he may horizontally adjust the position of the cutter wheel relative to the disks and may apply any desired amount of yielding pressure to the cutting disks that may be necessary to meet the requirements of necessary use.

I claim as my invention:

1. A disk sharpener, comprising a frame, a horizontally arranged supporting bar in the frame, a motor unit support slidingly and tiltingly mounted on said bar, a motor unit, comprising a motor and a cutting wheel fixed to the motor shaft, said motor unit being fixed to the motor unit support, a handle fixed to the motor unit for tilting it, a lever pivotally and rotatably connected to the motor unit support, and a fulcrum device for said lever, loosely and slidably mounted upon said supporting bar for gripping said supporting bar when the lever is in certain positions, and for sliding with the lever when the lever is in other positions whereby power may be applied directly to the bar for moving the motor unit relative to said bar.

2. In a disk sharpener, the combination of a frame having two parallel spaced apart horizontal beams, a lever extended vertically between the beams and having its lower end extended horizontally and inwardly beneath the under surfaces of the beams, a fulcrum plate fixed to the outer edge of the lever to engage the top surfaces of the beams, a friction plate applied to the lower end of the lever to engage the under surfaces of the beams, a screw seated in the upper end of the lever to engage and rotatably support a disk shaft, means for engaging and rotatably supporting the other end of a disk shaft, and means for rotating a disk shaft.

3. In a disk sharpener the combination of a frame having two parallel spaced apart horizontal beams, frame uprights at each end for supportingsaid beams, a shaft rotatably mounted on one of said uprights and parallel with andabove one end of said beams, a lever mounted vertically between the other ends of said beams and having its lower end extended horizontally and inwardly beneath the under surfaces of said beams, a fulcrum plate fixed to said vertical lever to engage the top surfaces of said beams, a friction plate applied to the inwardly extending portion of the lower end of said vertical lever to engage the under surfaces of said beams, a screw seated in the upper end of the vertical lever and in alinement with said rotatably mounted shaft wherein a disk shaft may be mounted to and between the inner end of said shaft and said screw with the disk shaft supported immediately above said beams whereby the said beams may serve as a rest for the disk when disconnected from the disk shaft supports.

4. A disk sharpener comprising a frame, means for rotatably supporting a disk shaft in said frame, a supporting bar in said frame substantially parallel with said disk shaft, a sleeve slidably and pivotally mounted on said bar, a prime mover support carried by said sleeve, including a bearing, a prime mover carried by said support, a shaft rotatably mounted in said bearing having one end connected to the drive shaft of said prime mover, a grinder fixed to the outer end of said shaft, a fulcrum arm slidably mounted bar, a lever pivoted to said arm having one end pivoted to said sleeve for moving said sleeve longitudinally of said bar, and a lever fixed to said prime mover for tilting said prime mover and the grinder carried thereby.

5. A disk sharpener, comprising a frame, means for rotatably supporting a disk shaft in said frame, a supporting bar in said frame substantially parallel with said disk shaft, a sleeve slidably and pivotally mounted on said, bar, a prime mover support carried by said sleeve, a prime mover including a grinder carried by said'prime mover support, a fulcrum arm slidably mounted on said bar, means for locking said arm to said bar, a lever pivoted to said arm having one end pivoted to said sleeve for moving said sleeve longitudinally of said bar and a lever fixed to said prime mover for tilting said prime mover and the grinder carried thereby. v

. ARTHUR M. RANDALL. 

